Lilith.

About Lilith

Lilith is a fictional character on The CW Television Network's drama and horror television series Supernatural. The series' writers conceptualized her as a dangerous new adversary for series protagonists Sam and Dean Winchester to face, introducing her to stabilize the story arc in the third season by giving demons a new leader in the wake of the death of the villainous Azazel and maintaining her as the primary antagonist until the conclusion of the fourth season. During the third season, Lilith tries to kill Sam and Dean, ordering for their deaths at the hands of her minions. Early in the fourth season, it was revealed that her goal was to free her maker, the fallen angel Lucifer, from his imprisonment in Hell. The protagonists' attempts to thwart her plan were the main plot of that season.